Stimulation of the heart via the sympathetic nerves would
A. decrease heart rate.
B. decrease stroke volume.
C. increase the force of ventricular contraction.
D. increase end-systolic volume.
E. not affect heart rate and force of contraction.
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Question 2) The baroreceptor reflex would cause which of the following events to occur if the reflex was caused by an increase in blood pressure?
A. increased parasympathetic stimulation of the heart
B. increased heart rate
C. increased cardiac output
D. increased force of contraction
E. increased sympathetic stimulation of the heart
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Question 3) The relationship between preload and stroke volume is known as
A. extrinsic regulation.
B. cardiac reserve.
C. Starling Law of the heart.
D. minute volume.
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Question 4) Which of the following factors would cause an increase in heart rate?
A. increased parasympathetic stimulation
B. stimulation of baroreceptors in the aorta
C. increased epinephrine release from the adrenal medulla
D. increased production of atrial natriuretic factor
E. vagal stimulation
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Question 5) Increased vagal stimulation would cause
A. the heart rate to decrease.
B. the heart rate to increase.
C. force of contraction to increase.
D. stroke volume to increase.
E. no change in heart rate, stroke volume, or force of contraction.
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Question 6) If the heart receives more sympathetic stimulation than parasympathetic stimulation, the heart will
A. increase its rate and force of contraction.
B. contract with greater force but at a slower rate.
C. decrease both its rate and force of contraction.
D. contract with less force but at a faster rate.
E. decrease rate, but increase force of contraction.
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Question 7) Within normal limits, an increase in preload leads to
A. an increase in cardiac output and force of left ventricular contraction.
B. a decrease in cardiac output and force of left ventricular contraction.
C. an increase in cardiac output and a decrease in force of left ventricular contraction.
D. a decrease in cardiac output and an increase in the force of left ventricular contraction.
E. a decrease in stroke volume and heart rate.
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Question 8) End-diastolic volume minus end-systolic volume is equal to
A. cardiac output.
B. cardiac reserve.
C. pulse volume.
D. venous return.
E. stroke volume.
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Question 9) Which of the following statements regarding intrinsic regulation of the heart is true?
A. Stretching the SA node will decrease generation of action potentials in the node.
B. Decreased venous return increases cardiac output.
C. The heart's pumping effectiveness is greatly influenced by small changes in afterload.
D. If cardiac muscle fibers are slightly stretched, they have a stronger contraction force.
E. If cardiac muscle fibers are slightly stretched, they have a weaker contraction force.
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Question 10) The dicrotic notch in the aortic pressure curve is due to the
A. increase in intraventricular pressure during ejection.
B. backflow of blood toward the ventricles.
C. closure of the left AV valve.
D. elasticity of the arterial wall.
E. closure of the semilunar valves.
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